Hot water heater

ABSTRACT

A hot water heater includes a substantially cylindrical upright tank having vertically-spaced upper and lower openings in its peripheral wall. A substantially helically coiled cylindrical conduit is threadable into the tank through the upper sidewall opening until its opposite end portions extend through the upper and lower sidewall openings. The helically coiled conduit is also threadable out through the upper sidewall opening for replacement. A hot liquid flows through the helically coiled conduit for heating water within the tank.

United States Patent 1191 1111 3,828,847 Stein Aug. 13, 1974 HOT WATER HEATER 3,130,779 4/1964 Huet 165/163 x 3,138,201 6/1964 Huet 165/163 [75] Invent ga Stem, North Royalton 3,335,790 8/1967 Aranyi etal. 165/163 x [73] Assignee: The Glass Lined Water Heater C o., Primary Examinercharles Myhre Cleveland, Ohio .Assistant Examiner-Theophil W. Streule, Jr. F1 d Feb 14 1973 Attorney, Agent, or Firm-Meyer, Tilberry & Body ie H 21 App]. No.1 332,260 57] ABSTRACT q A hot water heater includes a substantially cylindrical {52 us. Cl 165/76, 62/333, 126/361 upflgllt i P 1 P1 a lower 51 Int. (31 F28f 7/00 openmg? m l substamlafly hell- [58] Field-of Search 126/350 R, 361-368, Cally cmled cylmdncal q t d fi f the 126/378. 165/156 163 74 tank through the upper sidewall opening until its opposite end portions extend through the upper and lower sidewall openings. The helically coiled conduit [56] References Cited A is also threadable out through the upper sidewall UNITED STATES PATENTS opening for replacement. A hot liquid flows through 36238; 33;; gg 165/156 X the helically coiled conduit for heating water within 1, oore 2,022,431 11/1935 Parmelee tank 2,183,505 12/1939 Peet 3 Claims, 6 Drawing Figures PATENKDMIBI 31914 V 8.828.847

SHEEI Z'UF 2 HOT WATER HEATER BACKGROUND OF THE INVENTION This application pertains to the art of heating and more particularly to heating water. The invention is particularly applicable to heating water for domestic consumption with heat supplied from water used for heating. Although the invention will be so described, it will be appreciated that the invention has broader applications and may be used for other heating purposes.

One domestic heating system of a known type is commonly referred to as a radiator system. In such a system, a fuel burning heat exchange furnace heats water or other liquid in a large reservoinThe hot liquid is carried through conduits by way of valves and pumps to radiators located in a dwelling. Systems of the type described are commonly closed so that very little makeup liquid is necessary; Since very little makeup liquid is necessary, mineral deposits do not .rapidly collect within the system as commonly happens when large amounts of water are evaporated.

In heating systems of the type described, it is usually necessary to have a separate hot water heater for heating water to be consumed by members of the household in washing and the like. A separate water heater consumes a large amount of additional electrical energy or combustible fuel. A heating system of the type described often has more available heat in the reservoir than is called for by the control systems. Therefore, heat from the reservoir liquid is commonly wasted by radiation from the reservoir.

It would be desirable to have an efficient arrangement for using heat from hot liquid in the heating system for heating water to be consumed.

SUMMARY OF THE INVENTION A substantially cylindrical upright tank is connected with the reservoir of a heating system of the type described. The tank includes upper and lower ends connected by a peripheral wall. Vertically-spaced upper and lower openings are formed in the peripheral wall of the tank. A substantially helically coiled cylindrical conduit is threadable into the tank through its upper peripheral wall opening until its opposite end'portions project through the upper and lower peripheral wall openings. The coiled conduit is then connected to conduits communicating with the heating system reservoir.

Water flowing through the coiled conduit from the heating system reservoir then transfers heat to water in the cylindrical tank. Y

The helically coiled conduit includes a plurality of coils having an increasing pitch from the lower end portion toward the upper end portion thereof. This enables the coiled conduit to be threaded into and out of the upper peripheral wall opening of the tank. The coiled conduit has a longitudinal axis and a substantially uniform predetermined diameter. The opposite end portions of the coiled conduit extend substantially radially from its longitudinal axis and project outwardly beyond the predetermined diamter. The opposite end portions of the coil are substantially vertically spaced above one another.

The first coil of the helically coiled conduit adjacent the bottom end portion thereof has a pitch which is at least equal to the exterior radius of the tank. This enables the coiled conduit to be substantially horizontally positioned with its bottom end portion extending through the upper peripheral wall opening. The coil can then be rotated for threading the first coil into the tank. The coil is then tumable upwardly with its longitudinal axis extending at an angle of around 45 to the vertical. The coiled conduit can be further rotated until it is completely within the tank and its lower end portion extends out through the lower peripheral wall opening. I

In a preferred arrangement, the coiled conduit has a total length which is greater than two times the vertical height between the upper and lower peripheral wall openings.

It is a principal object of the present invention to provide an improved hot water heater.

It is another object of the present invention to provide a hot water heater with a helically coiled heat transfer conduit which can be threaded into and out of the tank through a small opening.

It is an additional object of the present invention to provide a hot water heater which enables use of standard tanks while providing optimum heat transfer from a conduit positioned within the tank.

BRIEF DESCRIPTION OF THE DRAWING FIG. 4 is a plan view showing the position of the conduit during an initial installation step;

FIG. 5 is a plan view showing a further step in the installation procedure; and

FIG. 6 shows the position of the conduit during a further installation step.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now the drawings wherein the showings are for purposes of illustrating a preferred embodiment of the invention only and not for purposes of limiting same, FIG. 1 shows a substantially cylindrical tank A constructed of 14 gauge steel and lined throughout its interior with porcelain enamel. Tank A includes upper and'lower end portions 12 and 14 welded to a cylindrical peripheral wall 16.

Tank A has a suitabe lower fresh water inlet opening 20 connected by a suitable fitting 22 with a conduit 24 leading to a pressurized fresh water source. Tank A also includes an upper outlet opening 26 connected by a suitable fitting 28 with an outlet conduit 30 leading to hot water spigots in a dwelling.

Periphral wall 16 has substantially vertically aligned upper and lower openings 34 and 36 through which opposite vertically aligned upper and lower end portions 38 and 40 of substantially helically coiled cylindrical conduit B extend. Opposite end portions 38 and 40 are connected by suitable fittings C with vertically-spaced conduits 44 which communicate with reservoir D containing hot liquid for use in a domestic heating system. Hot liquid from reservoir D may flow by convection upwardly through coiled conduit B for transferring heat to water within tank A. I-Iot liquid may also be pumped through coiled conduit B if so desired.

In accordance with one arrangement, tank A has an overall height between the exterior surfaces of ends 12 and 14 of around 58 inches. Tank A has an internal diameter of around 16 inches. With the'porcelain enamel coating, end plates 12 and 14, and peripheral wall 16, have a thickness of around 54 inch. The distance from the exterior surface of upper end 12 to the centerline of upper opening 34 is around 17 inches. The distance from the exterior surface of lower end 14 to the centerline of lower opening 36 is around 7 inches.

The fittings used for connecting coiled conduit B to conduits 44 may take many forms. One of such connections will be described with respect to opening 36 and it will be recognized that the connection for upper opening 34 may be the same. A metal plate 52 is suitably welded to the exterior surface of peripheral wall 16 in alignment with lower opening 36. Distance 54 from the outer surface of plate 52 to the inner surface of peripheral wall l6 adjacent opening 36 is around inch. Plate 52 has a threaded opening 56 therein aligned with opening 36. Threaded opening 56 has threads with a, peak diameter of substantially 1% inches. A compression fitting 58 is threaded into opencoiled conduit B and acts against a suitably cammed surface of fitting 58. An additional compression fitting as at 62 is threaded to fitting 58 for connecting conjduit 44 with end portion 40 of coiled conduit B.

Helically coiled conduit B is formed from threequarter inch OD copper tubing. The copper tubing is finned throughout all of its length between end portions 38 and 40. The finned portion of conduit B has an exterior diameter of substantially /8 inch. The end portions 38 and 40 of coiled conduit B/extending overaroundjlii to 4 inches, are smooth and have an exterior diameter of substantially 34 inch.

I-lelically coiled conduit B is dimensioned to have a dimension 70 of around 2 inches from the centerline of lower end portion 40 to first bend '72. Coiled conduit B has a dimension 74 of around 6 inches from first bend 72 to bend 76 defining the first coil of helically coiled conduit B. Conduit B has a dimension 78 between bend 76 to intermediate bend 80 of around inches. Conduit B has a pitch 82 between bend 80 and bend 84 terminating at the second coil of around seven inches. Coil B has a pitch between bend 84 and intermediate bend 86 of around nine inches as shown at 90. Coil B has a pitch 92 extending from bend 86 to the centerline of terminal end portion 38 of around 5 inches.

In a preferred arrangement, the total pitch from the centerline of terminal end portion 40 to bend 76 is slightly greater than'the exterior radium of tank A as measured from tank centerline 102. With such an arrangement, it is possible to position coiled conduit B with its longitudinal axis, which is coincidental with longitudinal axis 102, lying substantially horizontally as shown in FIG. 4. The first coil of conduit B will then hug the exterior sidewall of tank A as terminal end portion 40 is placed through upper opening 34. The inxes z p.ig hets zil P5 18 88849"? be rotated generally about its longitudinal axis for threading coil B into tank A. When coil B has been threaded through opening 34 up to around bend 76, coil B may be tilted upwardly as shown in FIGS. 5 and 6 so that its longitudinal axis extends at around 45 to the vertical. Further rotation of coil B about its longitudinal axis and jiggling thereof will enable conduit B to be completely positioned within tank A with its lowerend portion 40 extending through lower opening 36 and its upper end portion 38 extending through upper opening 34.

In the arrngement described, it will be recognized that it is important for helically coiled conduit B to have a plurality of coils which increase in pitch from lower end portion 40 toward upper end portion 38 thereof. This enables coiled conduit B to be threaded into one of the small openings while having a large coil diameter for achieving optimum heat transfer. In the arrangement described, helically coiled conduit B has a maximum external coil diameter of around 13 inches. All of the coils in helically coiled conduit B have this substantially uniform predetermined diameter. Opposite end portions38 and 40 of helically coiled conduit B are substantially vertically spaced above one another and extend substantially radially from the longitudinal axis of helically coiled conduit B. In addition, opposite end portions 38 and 40 project around three to four inches beyond the predetermined diameter of helically coiled conduit B.

Although the invention has been shown and described with respect to a preferred embodiment, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications and is limited only by the scope of the claims.

Having thus described my invention, I claim:

1. In a hot water heater of the type including a tank and two openings in the side of said tank adapted to receive the ends of a heating coil positioned in said tank, said heating coil being in the form of a conduit positioned in said tank and having opposite end portions projecting through said openings, said openings having a diameter not substantially greater than the exterior dimensions of said conduit, said conduit having a total length substantially greater than the distance between said openings and being in the shape of a helix with said end portions being straight and extending beyond the outer diameter of said helix, said end portions extending generally radially of said helix and parallel to one another, said helix having a plurality of convolutions of generally uniform diameter between said end portions, said convulutions including a first convolution extending from one of said end portions and having a first pitch length and succeeding convolutions each having a pitch length greater than that of the preceding convolution, said diameter of said helix and progressively increasing pitch lengths providing for said heating coil to be threadable into and out of said tank through one of said openings and when completely threaded into said tank, both ends of said conduit are positioned in a respective one of said openings with the center lines of the openings and ends being parallel.

2. The device of claim 1 wherein said tank is cylindrical having closed ends, said openings being positioned each tank end, said conduit having a total one adjacent a minimum diameter greater than the exterior diameter of said conduit and means threaded in said holes and coacting with said ends and threads in sealing engagement. 

1. In a hot water heater of the type including a tank and two openings in the side of said tank adapted to receive the ends of a heating coil positioned in said tank, said heating coil being in the form of a conduit positioned in said tank and having opposite end portions projecting through said openings, said openings having a diameter not substantially greater than the exterior dimensions of said conduit, said conduit having a total length substantially greater than the distance between said openings and being in the shape of a helix with said end portions being straight and extending beyond the outer diameter of said helix, said end portions extending generally radially of said helix and parallel to one another, said helix having a plurality of convolutions of generally uniform diameter between said end portions, said convulutions including a first convolution extending from one of said end portions and having a first pitch length and succeeding convolutions each having a pitch length greater than that of the preceding convolution, said diameter of said helix and progressively increasing pitch lengths providing for said heating coil to be threadable into and out of said tank through one of said openings and when completely threaded into said tank, both ends of said conduit are positioned in a respective one of said openings with the center lines of the openings and ends being parallel.
 2. The device of claim 1 wherein said tank is cylindrical having closed ends, said openings being positioned one adjacent each tank end, said conduit having a total length at least greater than two times the distance between said openings.
 3. The device of claim 2 wherein said tank has members welded thereto around said opening, said members each having threaded holes therethrough aligned with its respective conduit end, said threaded holes having a minimum diameter greater than the exterior diameter of said conduit and means threaded in said holes and coacting with said ends and threads in sealing engagement. 